Transfer ribonucleic acid nucleotidyltransferase activity in virions of type-C viruses.

A nucleotidyltransferase activity has been found associated with a number of mammalian and avian oncornaviruses. This activity catalyzes the incorporation of adenosine monophosphate and cytosine monophosphate into acid insoluble forms. The transferase activity from Rauscher murine leukemia virus has been characterized. The endogenous reaction is stimulated by various tRNAs particularly the 4S RNA isolated from Rauscher leukemia virus, whereas other RNAs have no effect. The product of the reaction is alkali and RNase sensitive, insensitive to DNase, and its size is similar to tRNA. Finally, the terminal nucleotide analysis of the product of the reaction indicates the presence of a CCA terminus. The properties of the activity found in the type-C viruses are in accord with those of known tRNA nucleotidyltransferases from other sources.